NASA science and technology are going to sea. A recently-developed instrument and NASA imaging technology are being employed in separate programs to explore two Pacific Ocean sites.

"Exploring the bottom of the sea is something like exploring in space," said James Edberg, head of the Undersea Technology Program at the Jet Propulsion Laboratory."The operating medium is significantly different but the requirements and constraints of operating in space are similar to those imposed in exploring the deep oceans," he said.

The first NASA undersea program existed from 1975 to 1981 when Edberg led a successful effort at JPL to develop and test an instrumented deep-sea platform.

In a paper presented before the Oceans '95 MTS/IEEE conference in San Diego, CA, in October, Edberg said JPL's current Undersea Technology program is really Phase II. In the earlier program, JPL developed the towed system for deep water survey called the Advanced Ocean Technology Development Platform, or AOTDP.

In his paper, Edberg listed a number of technologies developed under the NASA space program at JPL which have a potential for ocean applications. They include microelectronics, image processing, teleoperators and robotics, autonomous roving vehicles, advanced power sources, advanced communications and instruments and sensors.

Employing some of those technologies, JPL personnel recently designed and fabricated a three-axis geophone sensor package and delivered it to the Monterey Bay Aquarium Research Institute in Pacific Grove, CA. The institute placed the package in a hole bored in rock at a depth of 1,000 feet to monitor low frequency seismic activity in the underwater canyon in Monterey Bay.

Currently, Edberg and his team are working with JPL's Digital Imaging Animation Laboratory to process sonar data acquired by Dr. John Delaney, professor of Oceanography at the University of Washington. The data shows the Juan de Fuca Ridge, an active spread zone off the coasts of Washington and Oregon. The DIAL lab is processing the data into a graphic underwater video "flight" in and around the ridge areas.

A two-day seminar on NASA's undersea technology is being considered for early next year. The intent will be to introduce toi appropriate government agencies, academic institutions and industries the potential advantages which exist in using space program-developed-technology in the oceans.

During the first phase of the oceanography program, Edberg said, two significant advances were incorporated. One was the Galileo Project's spacecraft digital electronic system. It was adapted and used under water before the spacecraft was ever launched. The other was a portable shipboard data processing and display van, an integral part of the AOTDP system, which allowed the processing and display of data in real time, a first in the late 1970s.

The AOTDP operated from a surface ship. The primary scientific instruments were two JPL-developed digital side scan sonars designed to operate at depths of 20,000 feet. The system was towed on a three-quarter inch coaxial cable. Another instrument developed by JPL during that period was a "chirp" sonar, sub-bottom profiler, which was used in several research cruises with the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey.

A Chirp sonar scans a wide range of frequencies, some high, some low, and is able to determine the structure beneath the ocean floor for several feet, Edberg said. On one such cruise, the JPL instrument delineated the San Andreas fault on the ocean floor off Cape Mendocino.

Oceangraphic research institutions in England and Canada, as well as the United States, worked collaboratively with JPL in using the NASA space technology.

At the end of the program in 1981 the entire AOTDP system was transferred to Woods Hole Oceanographic Institution in Massachusetts where elements of the system were used during the development of the Argo/Jason vehicles that searched for and found the sunken Titanic in the north Atlantic.

The Undersea Technology program at JPL is within the Technology and Applications Directorate.